.header {
    width: 100%;
    height: 64px;
    background-color: #1d4ed8; // 深蓝
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 24px;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
    position: relative;
  }

  .logo {
    font-size: 20px;
    font-weight: bold;
  }

  .userSection {
    display: flex;
    align-items: center;
    position: relative;
    cursor: pointer;
    gap: 8px;
  }

  .avatar {
    width: 32px;
    height: 32px;
    border-radius: 9999px;
    background-color: white;
    color: #1d4ed8;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .dropdown {
    position: absolute;
    top: 56px;
    right: 0;
    width: 160px;
    background-color: white;
    color: black;
    border-radius: 6px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
    overflow: hidden;
    z-index: 10;
  }

  .item {
    padding: 10px 16px;
    cursor: pointer;
  }

  .item:hover {
    background-color: #f3f4f6;
  }
